So I bought the sonoline b Doppler when I was about 8 weeks. I'm currently 11+2 so when I didn't here the hb when I first got it I wasn't too upset cause it was early. I have been using it once a week since I got it, and nothing. Today I had a doctor appointment and the doctor used a Doppler and immediately after turning it on there's the hb. I don't understand why I can't find it with mine, my boyfriend has yet to go to a doctor appointment with me so I'm anxious to show him the babies hb. Anyone have ideas of what's going on?